The Glass Room by Ann Cleeves
The Glass Room is the fifth book in Ann Cleeves' Vera Stanhope series - now the major ITV detective drama Vera, starring Brenda Blethyn.
DI Vera Stanhope is not one to make friends easily, but her hippy neighbours keep her well-supplied in homebrew and conversation. But when one of them goes missing, her path leads her to more than a missing friend . . .
Vera tracks the young woman down to the Writer's House, a country retreat where aspiring authors work on their stories. Things get complicated when a body is discovered and Vera's neighbour is found with a knife in her hand.
Calling in the team, Vera knows that she should hand the case over. She's too close to the main suspect. But the investigation is too tempting and she's never been one to follow the rules.
There seems to be no motive. When another body is found, Vera suspects that someone is playing games with her. Somewhere there is a killer who has taken murder off the page and is making it real . . .
Also available in the Vera Stanhope series are The Crow Trap, Telling Tales, Hidden Depths, Silent Voices, Harbour Street and The Moth Catcher.